Phosphorus-containing sulfonyl-chlorides

ABSTRACT

A CLASS OF CHLOROSULFONATED PHOSPHORS ESTERS OF THE FORMULA:   ((R&#39;&#39;,(CL-O2S-)-PHENYL)-O-)M((R&#39;&#39;-PHENYL)-O-)N(R-)(3-M-N)-   P=O   WHERE R MAY BE LOWER ALKYL; R&#39;&#39; MAY BE CL, NO2, LOWER ALLKYL AND H; M IS AN INTEGER FROM 1 TO 3; N IS AN INTEGER FROM 0 TO 2; AND THE SUM OF M+N IS AN INTEGER FROM 1 TO 1 3. THESE COMPOUNDS FIND UTILITY AS INTERMEDIATES IN THE FORMATION OF SULFONYLHYDRAZIDES BY REACTION WITH HYDRAZINE. THE SULFONYL-HYDRAZIDES ARE USEFUL AS BLOWING AGENTS FOR RESINOUS BLENDS.

United States Patent ABSTRACT OF THE DISCLOSURE U.S.,Cl. 260-947 3Claims A class of chlorosulfonated phosphorus esters of the formula:

where R may be lower alkyl; R may be C1, N0 lower alkyl and H; m is aninteger from 1 to 3; n is an integer from 0 to 2; and the sum of m+n isan integer from 1 to' 3, These compounds find utility as intermediatesin the formation of sulfonylhydrazides by reaction with hydrazine. Thesulfonylhydrazides are useful as blowing agents for resinous blends.

This is a division of application Ser. No. 540,486 filed Apr. 6, 1966now US. Pat. No. 3,423,485.

This invention relates broadly to a new class of blowing agents forresinous blends and more particularly relates to a new class ofchlorosulfonated phosphorus-containing compounds useful as organicintermediates and to a new class of compounds particularly useful asblowing agents formed by reaction of the organic intermediates withhydrazine. The phosphorus-containing blowing agents of this inventionhave the capability of imparting fire retardancy to the extent they areincorporated in resinous foams;

The compounds of this invention are formed by initiallychlorosulfonating pentavalent phosphorus esters to form compounds of theformula:

These compounds are then reacted with hydrazine to formsulfonylhydrazides of the following formula:

In these formulas, R may be lower alkyl such as methyl and ethyl; R maybe halogen, N0 lower alkyl, and H; m is an integer from 1 to 3; n is aninteger from 0 to 2; and the sum of m+n is not greater than 3, i.e.m-i-n is an integer from I to 3.

Representative of pentavalent phosphorus esters useful in the practiceof this invention are the phosphates, phosphonates and phosphinates ofthe following formula:

a- (mi-n) (Ca- 21 a?) the pale, clear, yellow reaction mixture washeated to g Examples of phosphates useful in the practice of thisinvention are triphenyl phosphate, tri-o-, m-or p-tolyl phosphate andtri-o-, mor p-chlorophenyl phosphate. EX- amples of phosphonates arediphenyl methylphosphonate, diphenyl ethylphosphonate, di-o-, morp-tolyl methylphosphonate and the ethyl analogs thereof, and di-o-, morp-chlorophenyl methylphosphonate and the ethyl analogs there'of.Examples of phosphinates are 0-, mor ptolyl dimethylphosphinate, phenyldimethylphosphinate, 0-, mor p-chlorophenyl dimethylposphinate, and theethyl analogs such as o-tolyl diethylphosphinate.

The chlorosulfonated intermediates are readily formed by adding thepentavalent phosphorus ester to excess chlorosulfonic acid, at least twotimes the amount of chlorosulfonic acid required for addition of eachsulfonyl chloride group to the phenyl ring in accordance with thefollowing equations:

No solvent is needed for carrying out the reaction and preferably theaddition is carried out at a temperature of from about 2025 C. withcooling if necessary. Upon completing the addition, the reaction mixtureis heated at moderate temperatures, i.e. 50 C. or less, for at least 6hours or until HCl evolution ceases.

The chlorosulfonated derivatives are then reacted with hydrazine byadding hydrazine to a solution of the chlorosulfonated phosphorus esterin a polar solvent such as tetrahydrofuran or acetonitrile. The additionis made with stirring at low temperature (0 to 10 C.) and, uponcompletion of the addition, the stirred solution is allowed to warm toroom temperature. Usually a 5% to 10% molar excess of hydrazine isemployed, 2 moles of hydrazine per mole of sulfonyl chloride beingrequired to complete the reaction:

ice

The addition of hydrazine to the sulfonyl chloride as well as the lowreaction temperature are employed to minimize the competing reaction:

' Preparation of tris(p-chlorosulfonylphenyl) phosphate Triphenylphosphate 195.8 grams, 0.6 mole) was added in 20 minutes from a solidsaddition tube to stirred, freshly distilled chlorosulfonic acid (2,093grams, 18 moles) under a slight positive nitrogen pressure. Reactiontern-- peratures were maintained at 22 to 24 C. by means of an ice andwater bath during the addition of phosphate. The phosphate dissolvedalmost immediately and hydrogen chloride was evolved. Upon completingthe addition,

49 to 51 C. and maintained at this temperature range for 6. hours. Theresultant clear, pale amber reaction mixture was carefully addeddropwise to a suitable quantity of crushed ice (enough to maintaintemperature of about 5 C.). A white solid precipitate was filtered andpressed dry; the clear, slightly yellow filtrate was discarded.Twenty-nine hundred (2,900) milliliters of chloroform was added to thepowdered filter-cake and a relatively small water layer containing awhite semi-solid was separated from the lower, colorless, organic phase.After washing with three 25-ml. portions of chloroform, the aqueouslayer which still contained a white gelatinous solid was discarded. Thecombined chloroform solutions were washed consecutively with two 50-ml.portions of aqueous 10% sodium bicarbonate and three 100-ml. portions ofsaturated sodium chloride and dried over anhydrous magnesium sulphate.Concentration at reduced pres sure (pot temperature of 4050 C.) of thedried chloroform layer to approximately 500 m1. gave a white solidslurry. The slurry was diluted with 500 ml. of hexane, cooled to 0 andfiltered. The washed and dried filter-cake (304.4 grams) softened at 103C. and melted at 110- 118 C. Recrystallization of the reaction productfrom 3,000 ml. of a 3:1 carbon tetrachloride-benzene solution gave 265.3grams of the chlorosulfonated triphenyl phos phase melting at 115 ll9 C.

The recrystallized product was very soluble in chloroform, benzene,acetonitrile, dioxane, methyl ethyl ketone, methylene chloride anddiglyme. Hexane and petroleum ether failed to dissolve the product,whereas some degree of solubility was achieved in hot cyclohexane andcarbon tetrachloride.

Analysis.Calcd. for C H Cl O PS (percent): C, 34.77; H, 1.95; Cl, 17.11;P, 4.97; S, 15.47; mol. wt. 621.8. Found (percent): C, 34.96; H, 1.96;Cl, 17.19; P, 4.99; S, 15.70; mol. wt. 593.3 as determined in THF byvapor pressure osmometry.

EXAMPLE 2 Preparation of tris (p-hydrazidosulfonylphenyl) phosphateHydrazine (85%, 2.48 grams, 0.066 mole) Was added dropwise in 10 minutesto a stirred solution of the chlorosulfonated triphenyl phosphate ofExample 1 (6.21 grams, 0.01 mole) in 100 ml. of tetrahydrofuran at 4 C.Reaction temperatures were maintained at 510 C. during the addition ofhydrazine. After completing the addition, the reaction mixture wasstirred and left to Warm to room temperature over a period of 45minutes. Tetrahydrofuran insolubles filtered and dried gave a slightlygummy white solid (2.5 grams). The tetrahydrofuran filtrate was washedwith saturated sodium chloride, dried over magnesium sulphate, and thendiluted with 250 ml. of cold petroleum ether. A white solid precipitatedwhich, when filtered and dried, gave 4.6 grams of material melting at144-l47 C. (meq. of bromine required per gram=l8.7). Concentration ofthe tetrahydrofuran-petroleum ether filtrate left 0.7 gram of a solid,identified by melting point and mixture melting point as p-hydroxybenzene-sulfonylhydrazide.

The slightly gummy white solid obtained from the tetrahydrofuraninsoluble was largely soluble in water. Its aqueous a solution wascombined with the saturated sodium chloride washings from thetetrahydrofuran layer. Treatment of the aqueous solution with excessconcentrated sulfuric acid precipitated 3.3 grams of hydrazine sulphate,identified by melting point and mixture melting point.

The 4.6 grams of the crude white reaction product was dissolved indimethylformamide (13 ml.) and precipitated by addition to 100 ml. ofwater. The filtered precipitate, washed with alcohol and water anddried, melted at 155 157 C. with dec. On recrystallization fromacetonitrile and absolute alcohol (3:5 mixture) gave material melting at155.5 -157 C. with dec. (after drying at 80 Thermal Decomposition oftris(p-hydrazidosulfonylphenyl) phosphate Pure samples of the reactionproduct from Example 2 were decomposed in a gas decomposition apparatususing Nujol (mineral oil) and dibutyl phthalate as diluents. Thedecompositions were carried out at several temperatures andthe results,which appear in the following table, are

reported in terms of ml. of gas (at S.T.P.) per gramofsulfonylhydrazide. Infrared spectra of gaseous reaction products failedto indicate any absorption; nitrogen evidently is the only volatileproduct. In addition, qualitative tests failed to indicate the presenceof sulphur dioxide or hydrogen sulfide.

The gas yields were calculated based on the decomposition reaction:

Based on this reaction the theoretical ml. of gas per gram oftris(p-hydrazidosulfonylphenyl) phosphate is 110.5 ml. (based on Nevolved). In all cases, gas yields based on this decomposition reactionwere in excess of TABLE I M1. of gas per g. at Percent Half-life Dec.temp, C. S.T.P. field 1 130.5 (miu.) Diluent 105 3 Dibutyl phthalate.

107 97 29 N ujol.

Theoretieal ml. per gram=110.5 (based on E2 evolved).

EXAMPLE 3 Preparation of bis(p-chlorosulfonylphenyl) methylphosphonateDiphenyl methylphosphonate (63.3 grams, 0.26 rnole) was reacted with 602grams (5.1 6 moles) of chlorosulfonic acid in a manner similar to thatdescribed for triphenyl phosphate. Addition of the reaction mixture toice, extraction with chloroform and concentration of the combined,washed and dried chloroform extracts followed by dilution of theconcentrate (25.0 ml.) with pentane precipitated an oil. The solventlayer was decanted and the oil solidified on trituration with fresh icecold pentane. The filtered, washed and dried white solid (78.3 grams)melted at 8l-86 C. A second crop of product (13.6 grams), melting point8587.5C., was obtained upon dilution of the chloroform-pentane filtratewith the nonsolvent pentane. The combined fractions ofbis(p-chlorosulfonylphenyl)methylphosphonate melted at 83-86 C.

Recrystallization of the crude reaction product twice from a 50:50benzene-ligroine mixture raised the MP. to 84.5 87 C.

Analysis.Calcd. for C H Cl O PS (percent): C, 35.07; H, 2.49; Cl, 15.92;P, 6.95; S, 14.40; mol. wt. 445.24. Found (percent): C, 35.08; H, 2.60;Cl, 15.82; P, 7.02; S, 14.45; mol. wt. 457.0 (determined cryoscopicallyin benzene).

EXAMPLE 4 Preparation of bis (p-hydrazidosulfonylphenyl)methylphosphonate The bis(p chlorosulfonylphenyl)methylphosphonate (22.2grams, 0.05 mole) dissolved in acetonitrile (125 ml.) and maintained at4il C. was added in 1% hours with stirring, a solution of hydrazine 95%,7.42 grams, 0.22 mole) in 20 ml. of acetonitrile. Upon completing. theaddition, the reaction mixture, consisting of a finely divided whitesolid and a clear pale yellow solvent layer, was stirred at roomtemperature for one hour. The reaction mixture was cooled to 3 C. andfiltered. The filtercake, washed with fresh acetonitrile, was dried invacuo at room temperature to give 7.6 grams of a gummy pale pink solid.This was dissolved in water (35 ml.) to give a weakly basic solution.Neutralization of the aqueous solution followed by cooling failed toyield any solid. Addition of excess concentrated sulfuric acid, however,precipitated 13 grams (0.1 mole) of hydrazine sulfate identified by M.P.and mixture M.P. The strongly acidic aqueous solution was discarded.

The combined acetonitrile filtrate and washings were concentrated todryness at reduced pressure (pot temperature less 25 C.) and left asomewhat gummy white solid. The solid, washed with ether and dried invacuo, weighed 22.75 grams and melted at 118-124 C. with decomposition.A filtered solution of the solid in dimethylformamide (30 ml.) added towater (700 ml.) gave an oil. On cooling and scratching the oilsolidified. The resultant filtered white solid was washed consecutivelywith absolute alcohol and ether. The dried white solid weighed 17.35grams and melted at 130134 C. with decomposition.

A portion of the reaction product was precipitated from its solution indimethylformamide by addition to water and gave material melting at132134 C. with decomposition after drying in vacuo 1.0 mm.) atappromixately 80 C.

Analysis.Calcd. for C13H17N4O7PS2 (percent): C, 35.78; H, 3.93; N,12.84; P, 7.10; S, 14.70; meq. bromine per gram=18.4. Found (percent):C, 35.84; H, 4.27; N, 12.91; P, 7.12; S, 14.84; meq. bromine pergram=19.0.

The following examples illustrate the utility of thephosphorus-containing sulfonyl hydrazides as blowing agents for resinousblends.

EXAMPLE 5 Free-flowing particles (dry blend) of plasticizedthermoplastic vinyl resin were formed by mixing a masterbatch of thefollowing composition in a Henschel Blender at a temperature below about200 F.

Ingredient: Parts (grams) Polyvinyl chloride homopolymer having a numberave. mol. of 26,000 and a wt. ave. of 54,000 (determined by gelpermeation chromatography) 1,000

Dioctyl phthalate 700 Epoxidized soybean oil 50 Liquid ca-Zn octoatestabilizer 40 50 mesh limestone 100 TiO pigment 20 Calcium silicate 7.5

These particles were used to make vinyl sheets in accordance with eachof the following examples. In each example the dry blend was laid up to120 ml. thickness on a rubber bonded-asbestos fiber felt 0.019 inchthick. The dry blend compositions were then placed between two heatedplatens and held for given periods after which the fused sheets thatformed were cooled and stripped from the felt and examined. When ablowing agent was added to the masterbatch, it was intermately mixedtherewith by mixing in a Henschel Blender for about 15 minutes at roomtemperature.

EXAMPLES 6, 7, 8, 9 and 10 I 4,4-oxybis (benzenesultonylhydrazlde). 2Tris(p-hydrazldosulfonylphenyl) phosphate. 3Bis(p-hydrazidosultonylphenyl) methylphosphonate.

The sheet formed in accordance with Example 6 was well fused throughoutand flexible. It had a density of about 72.8 pounds per cubic foot. Thesheet formed in accordance with Example 7, using a commercial blowingagent, was a flexible fine celled foam having a density of about 35.9pounds per cubic foot. Both sheets formed in accordance with Examples 8and 9 were flexible fine celled foams having densities of 38.7 and 30.1pounds per cubic foot, respectively, although the sheet of Example 9 hada slightly coarser cell structure. The sheet of Example 10 was aflexible fine celled foam having a density of 38.1 pounds per cubicfoot.

The preferred percentage range for blowing agent is between about 1.0%to 5.0% by weight, based on the organic resin component.

We claim:

1. A compound of the formula:

wherein R is lower alkyl,

R is a member selected from the group consisting of chlorine, N0 loweralkyl, and H,

m is an integer from 1 to 3,

n is an integer from 0 to 2, and

m+n is an integer from 1 to 3.

2. The compound of the formula 3. The compound of the formula:

CHARLES B. PARKER, Primary Examiner A. H. SUTTO, Assistant Examiner US.Cl. X.R. 260923 968, 990

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,57,615 Dated y 1971 lnventofls) John E. Herweh and Algirdas C. Poshkus Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 1, line 26 the comma should be a period the last formula shouldappear as follows:

R -(m n) Column 2 line 10, "dimethylposphinate" should be--dimethylphosphinate--; the next to the last formula should appear asfollows:

the last formula should appear as follows FORM PO-l050 (IO-6 LISCOMM-DCGOS'IG-PGD U 5 GOVERNMENT PIINYING OFFICE 1 l9? D36B 33l UNITED STATESPATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,579,615 Dated May18, 1971 Inventor) John E. Herweh and Algirdas C. Poshkus PAGE 2 It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 3, lines 25 and 26 "phosphase" should be --phosphate--; line 62,"insoluble" should be --insolubles--; line 63, the "a" should becanceled; line 73, "On" should be --()ne--.

Column 4 line 6 in the formula, "H should be -H line 31 in the formula,"NOS" should be --HOS--; Table I in the first example, under theHalf-life column, the "3" should be --23--; line 46 in the note to TableI "H should be -N line 58, "25 .0" should be --250-.

Column 5 line 56 between "mol. and "of" insert --wt.-; last line "0.019"should be 0.039--.

Column 6 line 5 "intermately" should be --intimately--; Table II, Ex. 8,Masterbatch column "296.3" should be --296.5--.

Signed and sealed this 26th day of October 1971.

(SEAL) Attest EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting OfficerActing Commissioner of Patent FORM P0-1050 (IO-6 USCOMM-DC BOSIG-F'UO QU,S. GOVIIIIMENY PIINYING OFFICE llll OSIG-III

3. THESE COMPOUNDS FIND UTILITY AS INTERMEDIATES IN THE FORMATION OFSULFONYLHYDRAZIDES BY REACTION WITH HYDRAZINE. THE SULFONYL-HYDRAZIDESARE USEFUL AS BLOWING AGENTS FOR RESINOUS BLENDS.